Physics queries: LayerMasks

Layer masks are bitmasks that describe which layers are active or otherwise.

Active layers in the mask will be hit by the query.

A layer mask may be an int, but it doesn't represent a single layer.

int layerMask = 5;

int layerMask = LayerMask.NameToLayer("Name");

NameToLayer returns a layer index, not a bitmask.

Resolution

Correctly create a layer mask:

If bitmasks are confusing, a simple option is to serialize a LayerMask and configure it via the Inspector.

public LayerMask ExampleMask;

LayerMask can be passed to physics functions as it's implicitly convertible to int.

Double-check the mask value set in the inspector.

Initialise and use a mask created using LayerMask.GetMask.

Manually create a mask from layer indices using bit shifting.

Then pass that mask to the correct parameter of the query.